Such measuring devices, especially such measuring devices in the form of a temperature-measuring device, are known per se, for example, from DE 10 2005 037 921 B3. It is, however, problematic in case of measuring devices which are intended to be placed on the skin surface of the patient that the measuring device in question may become detached and a reliable measurement of the bodily function is thus no longer possible. Situations in which the measuring device is still located on the skin surface but it no longer has a sufficient contact with the skin surface for a reliable measurement result have proved to be especially problematic in this connection. The measurement of a body temperature of a newborn in an incubator may be mentioned as an example in this context, because the internal temperature of the incubator is regulated in relation to the measured body temperature. When a temperature-measuring device intended for this is still located on the skin surface of the newborn, it cannot be recognized based on the simple optical appearance whether the measured values supplied by the temperature-measuring device are reliable. When the temperature-measuring device has, in fact, already become partially detached from the skin surface, the internal temperature of the incubator is, for example, needlessly raised due to the temperature regulation based on a now erroneous measured value. This scenario is expressly an exemplary scenario only, and other examples can be created with other bodily functions monitored by a measuring device, and these examples which likewise illustrate that it is especially important to recognize whether the particular measured values supplied are reliable, consequently, whether the measuring device is still in contact with the skin surface of the patient to such an extent that reliable measurement results can be expected.
The above-mentioned DE 10 2005 037 921 B3 already pertains to this problem and proposes a possibility for how an insufficient skin contact of the measuring device can be detected.